Power Query Help

[Sajil]

Hi Mates,

I am looking to get help with my data, i wish to add new columns for current value based on latest date per row and highest& lowest value from the table per row and their respective changes from the current value.

The above is my date model, it shows my expected columns and results. 
Please for your consideration, i am using MS Office Standard 2019.

Appreciated your support , thank you.

[wdx223_Daniel]

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("dY9BDsAgCAT/wlkTwCpy7Cd6Mf7/G8U0aWOV42SyE2gNzguRIAAjp0gcORsoQg+P48Xl1027YlCd3XDy7dLicN8UA0InKvOh6e+qE1WD4jSHq86hOj9x7Jr9Bg==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Item Code" = _t, Date = _t, Value = _t]),
    ChangedType = Table.TransformColumnTypes(Source,{{"Date", type date}, {"Value", type number}}),
    Custom1 = Table.Group(
                          ChangedType,
                          "Item Code",
                          {
                           "n",
                           each let Rows=Table.RowCount(_),
                                    HighValue=List.Max([Value]),
                                    LowValue=List.Min([Value]),
                                    CurrentValue=List.Last([Value]),
                                    PreviousValue=List.Last(List.RemoveLastN([Value]),0)
                                in
                                    Table.FromColumns(
                                                      Table.ToColumns(_)
                                                      &List.Transform(
                                                                      {CurrentValue,
                                                                       HighValue,
                                                                       LowValue,
                                                                       CurrentValue-HighValue,
                                                                       (CurrentValue-HighValue)/CurrentValue,
                                                                       CurrentValue-LowValue,
                                                                       (CurrentValue-LowValue)/CurrentValue,
                                                                       PreviousValue,
                                                                       CurrentValue-PreviousValue,
                                                                       (CurrentValue-PreviousValue)/CurrentValue
                                                                      },
                                                                      each List.Repeat({_},Rows)
                                                                     ),
                                                      Table.ColumnNames(_)
                                                      &{
                                                        "CurrentValue",
                                                        "HighestValue",
                                                        "LowestValue",
                                                        "Change From HS",
                                                        "%",
                                                        "Change From LS",
                                                        "%2",
                                                        "Preivous Value",
                                                        "Change From PV",
                                                        "%3"
                                                       }
                                                     )
                          }
                         ),
    Custom2=Table.Combine(Custom1[n]),
    Custom3 = Table.Sort(Custom2,"Date")
in
    Custom3